Adjustable chair



FIG. 1 is a perspective view of an adjustable chair showing the design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is a left side view showing the bottom shelf of the adjustable chair in a raised position. 

The ornamental design for an adjustable chair, as shown and described. 